package com.ruoyi.gateway.filter;

import com.alibaba.fastjson.JSONObject;
import com.ruoyi.common.core.utils.ServletUtils;
import com.ruoyi.common.core.utils.StringUtils;
import com.ruoyi.gateway.config.properties.CaptchaProperties;
import com.ruoyi.gateway.service.ValidateCodeService;
import java.nio.CharBuffer;
import java.nio.charset.StandardCharsets;
import java.util.concurrent.atomic.AtomicReference;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Flux;

/**
 * 验证码过滤器
 *
 * @author ruoyi
 */
@Component
public class ValidateCodeFilter extends AbstractGatewayFilterFactory<Object> {
  private static final String[] VALIDATE_URL = new String[] {"/auth/login", "/auth/register"};

  @Autowired private ValidateCodeService validateCodeService;

  @Autowired private CaptchaProperties captchaProperties;

  private static final String CODE = "code";

  private static final String UUID = "uuid";

  @Override
  public GatewayFilter apply(Object config) {
    return (exchange, chain) -> {
      ServerHttpRequest request = exchange.getRequest();

      // 非登录/注册请求或验证码关闭，不处理
      if (!StringUtils.containsAnyIgnoreCase(request.getURI().getPath(), VALIDATE_URL)
          || !captchaProperties.getEnabled()) {
        return chain.filter(exchange);
      }

      try {
        String rspStr = resolveBodyFromRequest(request);
        JSONObject obj = JSONObject.parseObject(rspStr);
        validateCodeService.checkCaptcha(obj.getString(CODE), obj.getString(UUID));
      } catch (Exception e) {
        return ServletUtils.webFluxResponseWriter(exchange.getResponse(), e.getMessage());
      }
      return chain.filter(exchange);
    };
  }

  private String resolveBodyFromRequest(ServerHttpRequest serverHttpRequest) {
    // 获取请求体
    Flux<DataBuffer> body = serverHttpRequest.getBody();
    AtomicReference<String> bodyRef = new AtomicReference<>();
    body.subscribe(
        buffer -> {
          CharBuffer charBuffer = StandardCharsets.UTF_8.decode(buffer.asByteBuffer());
          DataBufferUtils.release(buffer);
          bodyRef.set(charBuffer.toString());
        });
    return bodyRef.get();
  }
}
